Modular hybrid transmissions are designed such that the transmission gearbox and torque converter (or launch clutch if there is no torque converter) are mostly carryover from a non-hybrid application. A separate assembly housing an engine disconnect clutch and a motor/generator is bolted between an engine and a transmission housing. The assembly housing the engine disconnect clutch and motor/generator may generally be referred to as the front module.
In a non-hybrid application that connects an engine output to a torque converter via a flexplate, the bolts connecting the torque converter to the flexplate are easily accessible through indentations on both sides of the engine, one of the indentations being the starter motor pocket. Also in the non-hybrid application, rotation of the torque converter is easily accomplished by rotating the starter ring gear. Having the ability to rotate the torque converter when connecting/disconnecting the flexplate allows the torque converter and flexplate to be indexed so that each bolt connecting the torque converter to the flexplate may be accessible through one of the indentations on either side of the engine at a given rotated position.
In a modular hybrid transmission application where the output of a motor/generator connects to a torque converter via a flexplate, the front module that is disposed between the engine and torque converter has a housing that does not have indentations for access to the bolts that connect the torque converter to the flexplate. In addition, neither the flexplate nor torque converter has features that are accessible to allow rotation of the torque converter.
It would be desirable to provide a modular hybrid transmission application where the bolts connecting an output of a motor/generator to a torque converter via a flexplate are accessible. It would also be desirable to provide a modular hybrid transmission application where the torque converter and flexplate may be indexed so that each bolt connecting the flexplate to the torque converter may be accessible at a given rotated position.